Epigenetics includes the study of gene activity controlled by the cells without actually altering the DNA sequence. Derived from the Greek word ‘epi’ meaning on or above, epigenetics refers to factors that act above or in addition to the genetic code. These changes occur in the form of subtle modifications that turn genes on or off and are typically attached to DNA rather than altering its sequence itself. These modifications are influenced by various factors such as environment, diet, stress, ageing and prenatal factors. While epigenetic changes are reversible, they can also be passed on from one generation to the next, a phenomenon known as intergenerational epigenetics. This aspect is particularly fascinating, but it also introduces uncertainty. If negative epigenetic changes are transferred, it can lead to serious implications compromising the health of many in future.
Mechanisms of Epigenetic Regulation
Epigenetic regulation primarily occurs through DNA methylation, where a methyl group is added to the cytosine bases of DNA, typically resulting in the repression of gene activity. Abnormal methylation is often linked to several diseases, including cancer. DNA is packed in cells by winding tightly around histone proteins. Modifications in histone in the form of methylation, acetylation or phosphorylation alter the packaging of DNA, allowing or preventing the transcription of specific genes. Another key player in epigenetic regulation is non-coding RNA, which can influence gene expression and contribute to the development of diseases like cancer and immune disorders.
Epigenetics in Health
Epigenetic changes, while potentially harmful, are essential for the normal development, differentiation, and tissue homeostasis. They play a crucial role in embryonic development, helping cells to differentiate into muscle, brain, skin cells and other tissues by activating or silencing certain genes. For instance, some genes will be turned off in muscle cells but active in nerve cells. Nutrients such as folate, vitamin B12 and methionine contribute to DNA methylation and epigenetic regulation. Studies suggest that poor diet or exposure to pollutants can leave lasting epigenetic impressions that affect health across generations. One hypothesis suggests that biological ageing can be quite accurately pinpointed by the changes in the DNA methylation patterns. Scientists believe reversing these age-related epigenetic changes may improve longevity and lead to the development of anti-aging therapies.
Epigenetics in Disease
Abnormal epigenetic changes can lead to several diseases. For example, dysregulation of DNA methylation can silence tumour suppressor genes, thereby allowing uncontrolled cell division and tumour formation. These changes along with aberrant histone modification results in abnormal brain development with diseases like Alzheimer’s, schizophrenia and autism. Epigenetic changes are also associated with inheritable conditions, such as rare forms of type 2 diabetes, which can arise from unchecked epigenetic modifications. Autoimmune diseases occur due to the failure of epigenetic marks in regulating immune system genes and encouraging the abnormal immune responses.
Therapeutic Applications
The reversible nature of epigenetic changes makes them ideal targets for therapies. Cancer treatments include drugs like histone deacetylase inhibitors and DNA methyltransferase inhibitors, which are currently in clinical trials, with the aim to restore normal gene expression patterns. CRISPR-Cas9 technology allows for precise epigenetic editing, enabling the harmful changes to be reversed without affecting the original DNA sequence.
Thus to conclude, epigenetics plays a central role in influencing our health through environmental, dietary, and lifestyle factors. Understanding and manipulating epigenetic marks holds the key to unlocking new directions in treating diseases like cancer, metabolic, and neurological disorders without any side effects. The study of epigenetic not only promises advancements in medicine but also offers insight into the correlation between lifestyle choices and long-term health outcomes across generations.
Deeksha, is a Biochemist and an aspiring neuroscientist. Her research interest lies at the intersection of molecular neuroscience and drug discovery.
